Threat Descriptions

Trojan:SymbOS/MultiDropper

Classification

Category :

Malware

Type :

Trojan

Platform :

SymbOS

Aliases :

Trojan:SymbOS/MultiDropper

Summary

Multidropper is a trojan-dropper that operates on Symbian Series 60 2nd Edition devices.

It drops and runs other malware components on the compromised device.

Removal

Disinfection for cases when phone cannot start up

CAUTION This method will remove all data on the device, including calendar and phone numbers.

  • Power off the phone
  • Hold the following three buttons down - "answer call" + "*" + "3"
  • Keep holding down the buttons and power on the phone
  • Depending on the model, you will either get text that reads "formatting" or a start-up dialog that asks for the initial phone settings
  • Your phone is now formatted and can be used again

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Trojan:SymbOS/MultiDropper is a family of trojan-droppers. The following details refer to variant MultiDropper.A.

MultipleDropper.A

Trojan:SymbOS/Multidropper.A is distributed as a SIS file. It drops Worm:SymbOS/CommWarrior.Z; Worm:SymbOS/Beselo.D; and Trojan:SymbOS/Kiazha.A onto the compromised device.

All of the dropped malware components are set to run on installation. The interaction of the various component malware is aiming to ransom money from the user.

  • Malware attempts to sign the user up to a QQ account
  • It also forwards SMS messages and data gathered from the phoneto the number defined by the malware author
  • Incoming and outgoing SMS are deleted
  • After a delay a warning message is displayed, telling the user to send money to the malware author to repair the phone

For the further details of malware functionality see detailed descriptions of included malware components: